Motorized kayak

ABSTRACT

A small, light weight watercraft that can be used and enjoyed in substantially the same manner as a conventional kayak, but one that includes a novel auxiliary power system for propelling the watercraft through the water. The auxiliary power system comprises a four-stroke, overhead-valve, single-cylinder engine that is of the character typically used to drive the cutting line head of a conventional line trimmer device. In one form of the invention, the speed of the engine can be controlled by a hand-operated throttle mounted on the kayak paddle. The conventional kayak has been modified by installing at the stem of the kayak an elongated, tubular-shaped duct having a water inlet port and by mounting within the hull of the kayak the engine system that includes a drive shaft that extends through the hull and into the tubular shaped duct to impart rotation to a propeller that is mounted on the drive shaft for controlled rotation within the tubular shaped duct.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates in general to small, motor powered watercraft. More particularly the invention concerns a specially modified, kayak-like watercraft having a gasoline powered engine mounted within the hull of the kayak. The motor has an elongated drive shaft that is adapted to drive a propeller that is rotatably disposed within a uniquely configured, tubular housing that is mounted within the stem of the watercraft and has a water inlet port in communication with the body of water through which the watercraft is propelled.

[0003] 2. Discussion of the Prior Art

[0004] A number of different types of small, motor powered watercraft, such as kayaks have been suggested in the past. One such watercraft is described in U.S. Pat. No. 5,481,997 issued to Arndt and entitled Water Jet Propelled kayak. The Arndt watercraft comprises a kayak having a kayak-style hull with one or more cockpits and an inboard power device that accelerates water and directs it out a steerable stem nozzle. The stem nozzle laterally redirects the accelerated water from the impeller over an angular range centered on a long axis of the hull.

[0005] Kayaks are well known in prior art and generally consist of a small double-ended watercraft having a displacement hull sometimes formed from a moldable plastic material. Typically, kayaks are propelled a manually by double ended paddle which is adequate for many purposes. However, when the kayak is going upstream or when the kayak is used for ocean sport, auxiliary power is beneficial.

[0006] A common type of auxiliary power plant found in small prior art watercraft is the so-called water jet drive. Such a drive is found in the previously discussed Arndt watercraft and is also discussed U.S. Pat. No. 3, 823,684 issued to Baggs. For example, the Arndt power plant comprises an impeller that receives water via a water intake and accelerates the water and urges it through an impeller duct to a funneling jet nozzle. The water is further accelerated as it is funneled by the jet nozzle to the stem nozzle, which is the searing nozzle. The Baggs power plant is somewhat similar and construction and includes a duct which is generally cylindrically shaped at the termination point of a drive shaft. A propeller is affixed to the end of the drive shaft and has a minimal tip to duct wall clearance. The duct is reduced in area aft of the propeller by approximately one-half the propeller disc area so as to accelerate the water as it is funneled into the nozzle-like reduced duct area.

[0007] The watercraft apparatus of present invention, which constitutes an improvement over the prior art, includes a unique power plant that can be quickly and easily installed within a conventional kayak. The power plant comprises a conventional four stroke, overhead valve, single cylinder engine having an elongated drive shaft. In the preferred form of the invention the power plant is of the character typically used to drive the cutting line head of a line trimmer type device that has become very popular for cutting grass, weeds, brush and the like. In the preferred form of the present invention, the drive shaft of the line trimmer has been modified to drive a propeller that is housed within a tubular shaped duct of uniform cross-section. The tubular shaped duct is mounted at the stern of the kayak and includes a strategically located water inlet port through which water is drawn by the propeller. In one form of the apparatus of the invention the speed of the engine is controlled by a hand-operated throttle that is mounted on the kayak paddle making the kayak ideal for use in the ocean. The engine is cooled by novel cooling means that is of a simple, but effective construction.

[0008] Unlike many of the prior art small powered watercraft, the watercraft of present invention is of a simple, easy to use, lightweight construction making it ideal for many different types of water sports. As will be better understood from the description that follows, most conventional prior art, commercially available kayaks can be readily modified to embody the novel power plant, cooling means and throttle control means of the present invention. Being a lightweight construction, the watercraft of the present invention can be easily transported on the roof of the car or in the back of a pickup truck. Additionally, the modified kayak of the present invention can easily be carried over dry land to and from the body of water where the kayak is to be used.

SUMMARY OF THE INVENTION

[0009] It is an object of the present invention is to provide a small, light weight watercraft that can be used and enjoyed in substantially the same manner as a conventional kayak, but one that includes a novel auxiliary power system for propelling the watercraft through the water.

[0010] Another object of the invention is to provide a water craft of the aforementioned character that is of a simple construction, is easy use and one that can be easily transported without the need of a boat trailer.

[0011] Another object of the invention is to provide a watercraft of the character described in the preceding paragraphs in which the auxiliary power system comprises a four-stroke, overhead-valve, single-cylinder engine that is of the character typically used to drive the cutting line head of a conventional line trimmer device.

[0012] Another object of the invention is to provide watercraft of the character described in the preceding paragraph in which the speed of the engine can be controlled by a hand-operated throttle mounted on the kayak paddle.

[0013] Another object of the invention is to provide a watercraft in the nature of a conventional kayak that has been modified by installing at the stern of the kayak an elongated, tubular-shaped duct having a water inlet port and by mounting within the hull of the kayak an engine of the character previously described that has a drive shaft that extends through the hull and into the tubular shaped duct to impart rotation to a propeller that is mounted on the drive shaft for controlled rotation within the tubular shaped duct.

[0014] Another object of the invention is to provide the watercraft of the character described in the preceding paragraphs that can be manufactured inexpensively and is easily maneuverable making it ideally suited for use in a number of environments including lakes, rivers and oceans.

DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is a side elevational view of one form of the powered watercraft of the invention shown here as a modified kayak-type apparatus.

[0016]FIG. 2 is a top plan view of the apparatus shown in FIG. 1.

[0017]FIGS. 3A and 3B, when considered together, comprise an enlarged view taken along lines 3-3 of FIG. 1 and partly broken away to show internal construction.

[0018]FIGS. 4A and 4B, when considered together, comprise a view taken along lines 4-4 of FIGS. 3A and 3B.

[0019]FIG. 5 is an enlarged, cross-sectional view taken along lines 5-5 of FIG. 4A.

[0020]FIG. 6 is an enlarged, fragmentary, cross-sectional view of a portion of the drive means of the invention showing the construction of the bearing that supports the drive shaft and one form of universal joint of the apparatus.

[0021]FIG. 7 is a view taken along lines 7-7 of FIG. 6.

[0022]FIG. 8 is a cross-sectional view taken along lines 8-8 of FIG. 4A.

[0023]FIG. 9 is a generally perspective, fragmentary view of the float device shown in FIG. 8.

[0024]FIG. 10 is a view taken along lines 10-10 of FIG. 8.

[0025]FIG. 11 is a view similar to FIG. 8, but showing the float device in an inverted, vent-opening closure position.

[0026]FIG. 12 is an enlarged, fragmentary view, partly broken away to show internal construction of one form of the manifold cooling device of the invention.

[0027]FIG. 13 is a view taken along lines 13-13 of FIG. 10.

[0028]FIG. 14 is a view taken along lines 14-14 of FIG. 13 partly broken away to show internal construction.

[0029]FIG. 15 is a view taken along lines 15-15 of FIG. 12.

[0030]FIG. 16 is a generally schematic view illustrating the throttle operating means of the invention controlling the speed of the engine component.

DESCRIPTION OF THE INVENTION

[0031] Referring to the drawings and particularly to FIGS. 1, 2, 3A, 3B, 4A, and 4B, one form of the powered watercraft of the invention is there illustrated. In this form of the invention, the watercraft comprises a modified, readily commercially available type of kayak. As best seen in FIGS. 1 and 2, the modified kayak here includes a hull 20, having a stern portion 20 a and a forward portion 20 b. Formed in hull 20 is an operator cockpit 22 and a spaced-apart top accessible compartment 24. Also formed in the forward portion of hull 20 is a storage compartment 26.

[0032] As shown in FIGS. 3A and 4A, a motor 30 is mounted within top accessible compartment 24 by transversely spaced apart mounting brackets 32 that are secured to hull 20 by suitable connectors 34. While motor 30 can take several forms, it is here shown as a gasoline powered, four-stroke, over-head valve, single-cylinder engine of the character used in commercially available line trimmers to rotatably drive the cutting line head that houses the cutting line used to cut grass, weeds and the like. Connected to the engine is an elongated, rearwardly extending drive shaft 36 (FIG. 4A). Various types of two or four stroke engines could be used for the present application, but an engine used in a line trimmer device, Model No. UNK 422 NNA manufactured and sold by Honda has proven quite satisfactory.

[0033] As illustrated in FIG. 4A, the conventional kayak has been modified by cutting away a portion of the underside of the stern area of the kayak and securely mounting, within the cut-away portion, a tubular member 40. Tubular member 40, which can be constructed from any suitable, rigid plastic material is generally circular in cross section throughout its length and has a first open end 40 a and a second end 40 b. Disposed intermediate ends 40 a and 40 b is a propeller compartment 40 c that houses a uniquely configured, five vane propeller 42 (see FIG. 5). Also disposed intermediate ends 40 a and 40 b of the tubular member is an inlet port 44 that is in communication with the body of water being traversed by the watercraft. In operation, water from the body of water is drawn into tubular member 40, through the inlet port 44 in the manner illustrated by the arrows 45 in FIG. 4A.

[0034] Fixedly mounted within second end 40 b of tubular member 40 is a support 48. Support 48 is generally disk shaped and, in a manner presently to be described, carries a bearing means for rotatably supporting the drive shaft 36 that extends through and is supported by support 48. Turning particularly to FIG. 6, the bearing means of the present form of the invention can be seen to comprise a conventional bearing assembly 50 that is interconnected with support 48 by suitable threaded connectors 51 in the manner shown in FIG. 6. Bearing assembly 50 comprises an outer housing 54 within which is mounted a pair of longitudinally spaced-apart conventional bearings 56 that function to rotatably support the rear portion 36 a of drive shaft 36. As illustrated in FIG. 6, the rear portion 36 a of the drive shaft is coupled with the forward portion 36 b of the drive shaft by means of a conventional universal joint generally designated in the drawings by the numeral 56. As best seen in FIG. 3A, forward portion 36 b of the drive shaft is operably interconnected with and controllably rotated by motor 30. With the construction shown in the drawings, rear portion 36 a of the drive shaft is cantilevered into tubular member in the manner best seen in FIG. 3a. Mounted at the rearward extremity of drive shaft portion 36 a is the previously identified propeller 42, which propeller rotates within support 40 in a manner to cause the water that is drawn into tubular member 36 through inlet 44 to be expelled forcibly from the tubular member in the direction indicated by the arrows 57 in FIG. 4A. It is this expelled water that propels the watercraft through the body of water.

[0035] An important feature of the powered watercraft of the present invention is cooling means that is carried by hull 20 for cooling motor 30. In the present form of the invention, this important cooling means comprises an exhaust manifold cooler 60 that is connected to one side of the motor 30 in the manner best seen in FIG. 20. The cooling means of the invention also comprises an oil pan cooler 62 that is connected to the oil pan of the motor in the manner illustrated in FIGS. 12 and 15. Considering first the oil pan cooler, it is to be noted that hull 20 includes a first water inlet 64 that is formed in the bottom wall of the hull 20 and is in communication with the body of water “W” through which the watercraft is propelled (FIG. 4B). One end 66 a of a first conduit 66 is sealably connected to water inlet 64 and a second, opposite end 66 b is connected to the oil pan cooler 62 in the manner shown in FIG. 12. As the watercraft moves through the water, water will flow through first conduit 66 and into the cooling chamber 67 of the oil cooler unit 62 to provide the cooling fluid for cooling the oil pan (FIGS. 12 and 15). After flowing through the oil pan cooling chamber, the water will flow into an exhaust conduit 68. Conduit 68 has one end 68 a connected to the oil pan cooler and an opposite end 68 b connected to support 48 in the manner best seen in FIG. 4A. In operation, it is apparent that as the watercraft moves through the water, water will flow into inlet 64 through first conduit 66 into the cooling chamber of the oil pan cooling unit 62 and then outwardly through conduit 68 to an outlet port 70 formed in support 48. Water flowing through outlet port 70 will flow into tubular support 40 and will then flow outwardly of the tubular support due to the urging of propeller 42.

[0036] The exhaust manifold cooler 60 of the cooling means comprises a second conduit 72 that has a first end 72 a that is connected to a second water inlet 74 that is formed in the bottom wall of the hull 20 and is also in communication with the body of water “W” through which the watercraft is propelled (FIG. 4B). At its opposite end 72 b conduit 72 is connected to the cooling chamber 73 of the exhaust manifold in the manner shown in FIG. 12. As the watercraft moves through the water, water will flow through second conduit 72 and into the cooling chamber of the exhaust manifold cooler unit 60 to provide the cooling fluid for cooling the exhaust manifold. After flowing through the cooling chamber of the exhaust manifold cooling unit, the water will flow into an exhaust conduit 76. Conduit 76 has one end 76 a connected to the exhaust manifold cooler and an opposite end 76 b connected to support 48 in the manner best seen in FIG. 3A. In operation, it is apparent that as the watercraft moves through the water, water will flow into inlet 74 through second conduit 72 into exhaust manifold cooling unit 60 and then outwardly through conduit 76 to an outlet port 80 formed in support 48. Water flowing through outlet port 80 will also flow into tubular support 40 and will then flow outwardly of the tubular support due to the urging of propeller 42.

[0037] Referring particularly to FIGS. 12 and 13, it is to be noted that the motor exhaust enters the manifold exhaust cooling unit through an inlet 80. The exhaust gas is then passed through a passageway 81 formed in the exhaust manifold cooling unit and exits the cooling unit via an outlet 82. From outlet 82, the now cooled exhaust gases flow into an exhaust conduit 84 that carries the exhaust gases to the exterior of the kayak (see also FIG. 14). It is obvious that as the gases flow through passageway 81, they will be cooled as a result of the cooling of the exhaust manifold by the water flowing through chamber 73.

[0038] Another important feature of the apparatus of the present invention is the novel throttle means for controlling the speed of the engine. As shown in FIGS. 3B and 16, this novel throttle means comprises a first, hand-operated throttle mechanism 88 that is mounted on kayak paddle 91 in the manner shown in the drawings. Throttle mechanism 88 includes a pivotally movable hand-operated lever 90 which is connected to a throttle cable that extends telescopically through a cable sheath 92. The throttle cable is interconnected with the carburetor of the motor 30 in a conventional manner as schematically shown in FIG. 16. As indicated in FIGS. 3B and 16, the cable sheath 92 that surrounds the throttle cable is interconnected with a tether 94, one end 94 a of which is connected to paddle 90 (FIG. 3B). At its opposite end, the tether is fixedly connected to the kayak hull. Tether 94 performs the important function of limiting the extent of travel of the paddle 91 away from the kayak hull so as to preclude accidental stretching or kinking of the cable sheath 92 that is connected to the tether by connectors generally designated in the drawings by the numeral 96. Tether 94 is long enough so that the paddle can be used in a normal fashion, but prevents the paddle from being extended away from the kayak a distance that would likely cause damage to the throttle system including the cable sheath and the throttle cable telescopically carried therewithin. The throttle control mounted on the paddle is particularly useful when the kayak is being used for ocean sports. For example, when the kayak is traversing ocean waves, the operator can controllably increase the speed of the engine and, accordingly, the speed of the kayak by simply operating the hand lever 90 that is conveniently mounted on the paddle and, in this way, provide additional power to the watercraft to smoothly traverse the ocean waves. The throttle means of the invention operates in a manner such that a pivotal movement of the handle 90 results in a telescopic movement of the throttle cable within the protective cable sheath and the concomitant movement of the throttle control carried by the carburetor “C” of the motor 30 (FIG. 16).

[0039] Also forming a part of the throttle means of the present invention is a second fixedly mounted throttle unit generally designated in the drawings by the numeral 100. Throttle unit 100 is mounted on one side of the kayak hull in the manner shown in FIG. 3B and is operated in a conventional manner by a push/pull control mechanism 102 that is interconnected with a throttle cable, which, in turn, is interconnected with the throttle control carried by the carburetor (FIG. 16). With this novel construction, the speed of the motor can be controlled either through the hand-operated throttle control that is connected to the paddle 91, or in the alternative, by the throttle unit 100 that is fixedly mounted on the hull of the kayak.

[0040] As depicted in FIG. 16, the carburetor “C” of the motor 30 is appropriately interconnected via supply lines 103 with a gasoline tank 104 that is mounted within the hull of the kayak in the manner shown in FIGS. 3B and 4B. With the arrangement shown in the drawings, gasoline tank 104 can be conveniently filled through a capped fill port 106 that is accessible from the top of the kayak hull in the manner indicated in FIGS. 3B and 4B. Fill port 106 is appropriately interconnected with the gasoline tank by a fill tube 105.

[0041] Yet another unique aspect of the apparatus of the present invention resides in the fact that the starter pull rope 108 that is used to start the motor 30 in a conventional manner is readily accessible from the top of the kayak hull in the manner indicated in FIG. 3A. More particularly, as indicated schematically in FIG. 16, the pull rope 108 extends through an aperture 110 formed in the kayak hull so that when the handle portion 108 a of the pull rope mechanism is pulled outwardly from the exterior of the kayak hull, the motor 30 can be started in a conventional manner.

[0042] Another important feature of the watercraft of the present invention resides in the novel closure means of the device for closing the top accessible compartment 24 that houses motor 30. In the present form of the invention, this closure means comprises an oval shaped cover member 110 that sealably closes the top open compartment 24 in the manner indicated in FIGS. 2 and 4A. Member 110 is preferably formed of a yieldable plastic material and includes a peripheral portion 110 a (FIG. 4B) that can be secured into sealing engagement with the peripheral opening of the top accessible compartment 24 in a manner to provide a watertight seal.

[0043] Also forming a part of the closure means of the present form of the invention is a tubular member 114 that extends through and is sealably connected to cover member 110 by an appropriate sealing ring 116 that is sealably connected to and circumscribes tubular member 114 (FIG. 8). Tubular member 114 has an upper portion 114 a that, in normal operation, extends above cover 110 and a lower portion 114 b that extends below cover member 110. Formed in upper portion 1 14 a of support 114 is an air inlet opening 118 that normally permits air to flow from atmosphere into the lower portion of tubular member 114 b in the manner indicated by the arrows 119 in FIG. 8. Air flowing from atmosphere into tubular support 114 will then flow freely into the engine compartment. Formed within the lower portion of member 114 is a multiplicity of spaced-apart vent openings 122.

[0044] A unique aspect of the closure means resides in the provision of plug means for closing air inlet opening 118 in the event that the kayak is accidentally inverted. This plug means here comprises a buoyant plug 124 that is normally maintained in the upper position illustrated in FIG. 8 by biasing means shown here as a coil spring 126. One end of coil spring 126 is connected to a cross bar 128 that extends transversely of member 114 and the other end is affixed to buoyant plug 124 by means of connector element 129 (FIG. 9) so as to continuously urge the plug into the uppermost position shown in FIG. 8. However, should the kayak be accidentally inverted, moving the closure means into the position shown in FIG. 11, water will, of course, flow into tubular member 114 causing the buoyant plug 124 to move upwardly in the direction of the arrow 129 of FIG. 11 against the urging of spring 126. Upon the plug reaching the position shown in FIG. 11, the plug sealably close inlet opening 118 thereby preventing water from flowing into the engine compartment and into the hull of the kayak while the kayak is in the inverted position.

[0045] A similarly configured, second closing means is mounted within hull 30 forwardly of the tubular member 114 in the manner shown in FIG. 4B. This second closure means functions to close an opening 130 formed in the kayak hull intermediate the operator compartment 22 and top accessible compartment 24. This second closure means is of similar construction and operation to the closure means previously described and includes a buoyant plug that, in the event the kayak is inverted, will function to seal an air inlet opening 132 formed in a tubular member 134. More particularly, the construction of the second closure member is such that if the kayak is inverted in the manner shown in FIG. 11, the buoyant plug that is telescopically movable within member 134 will be moved into a sealing position such as that shown in FIG. 11 to seal opening 132 against the flow of water into the interior of the kayak hull.

[0046] It is apparent that the first and second closure means of the invention permit the adequate flow of air into and out of the interior of the hull during normal operation and, at the same time, prevent water from flowing into the interior of the hull in the event that the kayak is accidentally inverted.

[0047] In operation of the watercraft of the invention, motor 30 can be conveniently started from the exterior of the watercraft by pulling on the pull rope handle 108 a which is readily accessible from the top of the kayak hull. With the motor running, the operator can be comfortably positioned on a seat 136 that is mounted within the operator's cockpit 22 in the manner shown in FIG. 4B. When seated within the cockpit, the operator can conveniently grasp the paddle 91 with both hands and then by gripping the throttle handle 90 with the right hand can precisely control the speed of the engine while at the same time propelling the kayak through the water by use of the paddle 91. Direction of the kayak can be controlled in a conventional manner by foot pedals mounted within the operator's cockpit that are interconnected with a conventional rudder assembly that is generally designated in the drawings by the numeral 140. As previously mentioned, when the watercraft is used for ocean sport, the throttle mounted on the paddle is extremely useful in adding power to the watercraft to enable it to smoothly ride over ocean waves and through strong ocean currents.

[0048] Having now described the invention in detail in accordance with the requirements of the patent statutes, those skilled in this art will have no difficulty in making changes and modifications in the individual parts or their relative assembly in order to meet specific requirements or conditions. Such changes and modifications may be made without departing from the scope and spirit of the invention, as set forth in the following claims. 

I claim:
 1. A powered watercraft for traversing a body of water comprising: (a) a hull having a stem portion, an operator's cockpit and a top accessible compartment located between said stem portion and said operator's cockpit; (b) a motor mounted within said top accessible compartment, said motor having a drive shaft; (c) a tubular member mounted within said stem portion, said tubular member having a first open end and a second end, said tubular member further including a propeller compartment and an inlet port located between said first and second ends, said inlet port communicating with the body of water being traversed by the watercraft; (d) a support disposed within said second end of said tubular member, said drive shaft extending through and being supported by said support; and (e) propeller connected to said drive shaft for rotation within said propeller compartment.
 2. The powered watercraft as defined in claim 1, in which said support includes bearing means for rotatably supporting said drive shaft of said motor.
 3. The powered watercraft as defined in claim 1 further including cooling means carried by said hull for cooling said motor.
 4. The powered watercraft as defined in claim 1 in which said hull is provided with a water inlet in communication with the body of water being traversed by the watercraft and in which a cooling means comprises a first conduit interconnecting said water inlet with said motor.
 5. A powered watercraft for traversing a body of water comprising: (a) a hull having a cooling water inlet in communication with the body of water, a stem portion, an operator's cockpit and a top accessible compartment located between said stem portion and said operator's cockpit; (b) a gasoline powered motor mounted within said top accessible compartment, said motor having a drive shaft; (c) a tubular member mounted within said stem portion, said tubular member having a first open end and a second end, said tubular member further including a propeller compartment and an inlet port located between said first and second ends, said inlet port communicating with the body of water being traversed by the watercraft; (d) support means for closing said second end of said tubular member, said drive shaft extending through and being supported by said support means; (e) a propeller connected to said drive shaft for rotation within said propeller compartment; and (f) cooling means carried by said hull for cooling said motor, said cooling means comprising; (i) an oil pan cooler connected to said motor, said oil pan cooler having a water inlet and a water outlet; (ii) a first conduit interconnecting said cooling water inlet in said hull with said water inlet of said oil pan cooler; and (iii) a second conduit interconnecting said water outlet of said oil pan cooler with said support means.
 6. The powered watercraft as defined in claim 5 in which said hull is provided with a second water inlet and in which said cooling means further comprises: (a) an exhaust manifold cooler connected to said motor, said manifold cooler having a water inlet and a water outlet; (b) a third conduit interconnecting said second water inlet with said inlet of said exhaust manifold cooler; and (c) a fourth conduit interconnecting said water outlet of said exhaust manifold cooler with said support means.
 7. The powered watercraft as defined in claim 5 further including a paddle for use in moving the watercraft through the water and in which the powered watercraft includes throttle means carried by said paddle for controlling said motor.
 8. The powered watercraft as defined in claim 5 in which said propeller includes six circumferentially spaced vanes.
 9. The powered watercraft as defined in claim 5 further including closure means for closing said top accessible compartment.
 10. The powered watercraft as defined in claim 9 in which said closure means comprises: (a) a cover member for sealably closing said top accessible compartment; (b) a tubular member sealably connected to said cover member and extending therefrom, said tubular member including an upper portion having an opening and a lower portion; (c) a sealing ring disposed intermediate said upper and lower portions of said tubular member; and (d) plug means disposed within said upper portion of said tubular member for telescopic movement between a first position and a second position wherein said plug closes said opening in said upper portion of said tubular member.
 11. The powered watercraft as defined in claim 10 in which said plug means comprises a generally cylindrically shaped, buoyant plug.
 12. The powered watercraft as defined in claim 11 further including biasing means for biasing said plug means toward said first position.
 13. A kayak apparatus for traversing a body of water comprising: (a) a hull having a stern portion, said operator's cockpit and a top accessible compartment located between said stern portion and said operator's cockpit; (b) a gasoline powered motor mounted within said top accessible compartment, said motor having a drive shaft and a throttle means, including a hand control for controlling speed of the motor; (c) a paddle for moving the watercraft through the water, said hand control of said throttle means being mounted on said paddle; (d) a tubular member mounted within said stern portion, said tubular member having a first open end and a second end, said tubular member further including a propeller compartment and an inlet port located between said first and second ends, said inlet port communicating with the body of water being traversed by the watercraft; (e) support means for closing said second end of said tubular member, said drive shaft extending through and being supported by said support means; and (f) a propeller connected to said drive shaft for rotation within said propeller compartment.
 14. The powered watercraft apparatus as defined in claim 13 further including closure means for closing said top accessible compartment.
 15. The powered watercraft apparatus as defined in claim 13 in which said closure means comprises: (a) a cover member for sealably closing said top accessible compartment; (b) a tubular member sealably connected to said cover member and extending therefrom, said tubular member including an upper portion having an opening and a lower portion; (c) a sealing ring disposed intermediate said upper and lower portions of said tubular member; and (d) plug means disposed within said upper portion of said tubular member for telescopic movement between a first position and a second position wherein said plug closes said opening in said upper portion of said tubular member, said plug means comprising a generally cylindrically shaped, buoyant plug.
 16. The watercraft apparatus as defined in claim 13 in which said hull is provided with the first and second water inlet ports in communication with the body of water and in which the watercraft further includes cooling means carried by said hull for cooling said motor.
 17. The powered watercraft apparatus as defined in claim 16 in which said cooling means comprises: (a) an oil pan cooler connected to said motor, said oil pan cooler having a water inlet and a water outlet; (b) a first conduit interconnecting said cooling water inlet in said hull with said water inlet of said oil pan cooler; and (c) a second conduit interconnecting said water outlet of said oil pan cooler with said support means.
 18. The powered watercraft apparatus as defined in claim 16 in which said cooling means further comprises: (a) an exhaust manifold cooler connected to said motor, said exhaust manifold cooler having a water inlet and a water outlet; (b) a third conduit interconnecting said second water inlet with said inlet of said exhaust manifold cooler; and (c) a fourth conduit interconnecting said water outlet of said exhaust manifold cooler with said support means.
 19. The powered watercraft apparatus as defined in claim 16 in which said support means includes bearing means for rotatably supporting said drive shaft.
 20. The powered watercraft apparatus as defined in claim 19 in which said propeller includes six circumferentially spaced vanes. 